I've been to Kool Haus a few times each year. I'm there more because of the musical acts that play there - whether this applies to you, that depends on whether you like who plays there! But still, there are a lot of variety as to who comes to play there. I've seen Underworld, Muse, moby, thievery corporation...and the ticket prices are reasonable (though not cheap) - figure on paying $35. (But compare that to seeing a band you love play at a huge venue and you paying $100).
It's a good place if you like to rock out...the stage is pretty wide so the floor room is too. That way you're not so far off from a good view.
Acoustics aren't the greatest there. Getting there is pretty decent although still a trek to get from the TTC (but that's because the TTC is $#!t.